The sun is seen after dawn near Exeter. Photograph: Toby Melville/Reuters

The dust has caused shorter-wavelength blue light to be scattered, making it appear red. “Ophelia originated in the Azores, where it was a hurricane, and as it tracked its way northwards, it dragged in tropical air from the Sahara,” King said.

“The dust gets picked up into the air and goes high up into the atmosphere, and that dust has been dragged high up in the atmosphere above the UK.”

Red skies over London - in pictures

Read more

The Met Office said the vast majority of the dust was due to forest fires on the Iberian peninsula, which have sent debris into the air. This has been dragged north by Ophelia.

Ophelia also pulled in unusually warm air from Spain and north Africa, which is why temperatures reached the early 20s over the weekend.

“An interesting phenomena that is a result of the movement of ex-Ophelia is the colour of the sky and the sun this morning, and dust on cars,” the Met Office said.

“The same southernly winds that have brought us the current warmth have also drawn dust from the Sahara to our latitudes, and the dust scatters the blue light from the sun, letting more red light through much as at sunrise or sunset.”